1. Field of the Invention
The embodiments of the invention provide a method, apparatus, etc. for a cache arrangement for improving RAID I/O operations.
2. Description of the Related Art
It is often necessary in a distributed storage system to read or write data redundantly that has been striped on more than one storage server (or target). Such a system configuration is referred to as a “network-RAID” (redundant array of independent disks) because the function of a RAID controller is performed by the network protocol of the distributed storage system by coordinating I/O (input/output) operations that are processed at multiple places concurrently in order to ensure correct system behavior, both atomically and serially. Distributed storage systems using a network-RAID protocol can process, or coordinate, a network-RAID-protocol I/O request (I/O request) locally at a client node or the request can be forwarded to a storage server or a coordination server for processing. For example, one client node may locally write data to a particular data location, while another client node may choose to forward a read or a write request for the same data location to a shared, or coordination, server.